1. Field of Invention
This invention relates to wind powered, sail propelled bicycles, or pedal cycles, especially those used for transportation or recreation.
2. Description of Prior Art
Sailing is defined within many authoritative references, and involves the use of wind power and sails to propel a sailboat. There is no definite term for a sailing bicycle, or a Sailbike.
A true, wind powered, sail propelled vehicle, must be capable of traveling on a course which includes all points of sail common to other successful sailing vessels, and this must include beating to windward, reaching and running before the wind. This course must include headings throughout 270 degrees relative to the winds' direction. Maneuvers that change the vehicles' direction must include tacking, and jibing, and these must be safely executed with immediacy, and without hesitation or delay. The variation of the winds' strength and direction also require that constant trimming adjustment be made to the sails' position. To prevent the sail from trapping the force of a powerful gust of wind, it must be capable of an immediate release all of the force of the wind, while in any position of operation, or during any maneuver. The requirements for sustained operation of the sail and the vehicle it powers must be within the physical limits of its operator.
Prior art in the field of sailing land vehicles indicate a variety of unique solutions have addressed the physical difficulties associated with the placement of a sail rig onto a bicycle, or pedal cycle. However, these previous attempts can be characterized as mechanically complicated devices that are quite unlike the simple sails, masts, and rigging found on successful contemporary sailing vessels, and they all fail to perform as a true sailing vehicle. These failures are categorized as follows:
1. They do not functionally or safely sail course headings throughout 270 degrees relative to the wind's direction, and their courses sailed do not include, beating, reaching, and running before the wind;
(a) evidenced by sails of other than wing shapes, that do not create adequate lift, and PA1 (b) evidenced by sails asymmetrically positioned about vehicles' longitudinal axis, and PA1 (c) evidenced by sails without a boom or supporting outboard spar, especially where these are sheeted to the center of the vehicle's longitudinal axis, and PA1 (d) evidenced by sails that cannot be properly trimmed or shaped to the changing configuration of the wind, and PA1 (e) evidenced by undersized sail areas. PA1 (a) evidenced by long booms or sails with long foot dimension, and PA1 (b) evidenced by vehicles with multiple sails, and PA1 (c) evidenced by sails positioned lower than the bicycle frame, and PA1 (d) evidenced by sails that require unusual efforts to trim or reposition, and PA1 (e) evidenced by sails that cannot be retrieved after being fully released. PA1 (a) evidenced by sails that cannot be continually viewed by the operator, and PA1 (b) evidenced by vehicles with multiple sails, and PA1 (c) evidenced by sail rigs that lack the proper sail trimming hardware, and PA1 (d) evidenced by automatic, self trimming apparatus. PA1 (a) evidenced by sails positioned lower than the bicycle frame, and PA1 (b) evidenced by sails located behind the operator. PA1 (a) evidenced by booms or sheets positioned above, and requiring the operator to manipulate, above the operators' head, and PA1 (b) evidenced by absence of proper mechanical purchase on sail trimming sheets, and PA1 (c) evidenced by long booms that generate large rotational forces, and PA1 (d) evidenced by unusual requirements to tether the operator's body to the sail. PA1 (a) evidenced by designs requiring unique non-standard bicycle frame configurations, and PA1 (b) evidenced by attachments that limit non-sailing uses of the bicycle, and PA1 (c) evidenced by attachments that are structurally inadequate to resist the applied forces. PA1 (a) evidenced by absence of any pedals, and PA1 (b) evidenced by long sail trim sheets.
2. They maneuver poorly and cannot tack or jibe quickly and safely;
3. They are not capable of continuous sail trimming;
4. They trap the wind and are unable to release it fully, while in any position or during any maneuver,
5. They require physical strength or balance, that the operator cannot perform or maintain over a sustained period of operation;
6. They do not attach readily to standard bicycles, or pedal cycles,
7. They interfere with the operator's simultaneous use of the vehicles means of pedal propulsion:
U.S. Pat. No. 94,731 (Couder, 1909) is a two sail, schooner type rig which cannot produce adequate lift necessary for beating to windward. The foresail utilizes no boom or pole and it's clew is sheeted directly to the longitudinal axis of the bicycle frame. The resulting angle of the sail will not generate sufficient lift for beating to windward, and must be held outboard, by hand, to function when reaching or running. There is no means to prevent the free end of the foresail spar from rotating vertically upward. This will loosen the jib luff tension, severely distort the jib's shape, and render the sail useless during up wind sailing. The foresail spar and the main mast rely on a friction clamp means to resist horizontal rotational forces at their attachment to the bicycle frame. Both are likely to fail. The main sail is located behind the operator, and cannot be continuously trimmed, nor fully release a gust of wind.
U.S. Pat. No. 2,038,166 (Deal, 1935) is a rear positioned sail, with a relatively long foot. To trim the sail a rider must operate a lever which is located behind their back. This lever has a very large negative mechanical relationship to the boom, and is likely to fail to function properly. The vehicle cannot be continuously operated, or continuously trimmed, and cannot perform a controlled tack or jibe maneuver. There is no evidence that the wind force in the mainsail can be fully released.
U.S. Pat. No. 3,836,176 (Yivisaker, 1974) is a small forward positioned, square shaped sail. Its symmetric shape requires the wind to pass over the sail from both its luff side and its leech side on alternating tacks. Lacking a means of reconfiguring the sails' draft location, it cannot develop lift and will not sail to windward. This lack of proper lift also renders this solution totally inadequate for reaching. In the running configuration, the sail's small shape is generally blanketed by the wind shadow from the riders' own body, and provides only a slight improvement for down wind sailing. The wind force in the sail cannot be fully released. The friction clamp means of attachment and sail trimming will not function if a larger sail or alternate sail shape is substituted.
U.S. Pat. No. 3,994,508 (Danner, 1976) is an asymmetrical, side-mounted rig, with an exceptionally long boom and long loose footed sail. This device unsuccessfully attempts to eliminate the operator's need to maintain continuous sail trim with an alternative, self trimming mechanical means. The rig also utilizes a spring mechanism at the mast step, and a boom that flexes but does not rotate. The fixed boom position along the longitudinal axis is set up for a beating configuration. However, the long loose footed sail is extremely inefficient for that purpose. The lack of standard sail sheet trimming eliminates the operator's ability to effectively control the sail's leech tension, which is an important sail trimming function. The lack of a movable outboard spar prevents the sail from being properly shaped or adjusted for running or reaching. There is no apparent means to release the wind force in the sail at any time.
U.S. Pat. No. 4,441,728 (Schroeder, 1984) is a rear-mounted circular sail rig. This sail cannot be continuously trimmed, and the wind force cannot be fully released. The non-wing shaped sail is not capable of generating proper lift. Therefore, the vehicle has is no potential to sail upwind, and reaching is severely restricted. The true sailing angle is likely limited to approximately ninety degrees of downwind sailing.
U.S. Pat. No. 4,557,495 (Kindermann, 1985) is an asymmetrical, front mounted sail rig, with a long footed sail and boom positioned next to the operator and extending nearly to the ground. This long boom creates a large rotational force in the sail which is difficult for the operator to control. To reposition this sail onto a new tack it is necessary to rotate the sail and a portion of the mast, vertically upward and over the operator's head. Consequently, it cannot be tacked or jibed while underway. To maintain sail trim, the rider's body must be tethered to the sail. When the sail is fully released while running, it swings uncontrollably forward and upward overhead, beyond the reach of the operator. When the sail is back winded, it is immediately pinned against the side of the vehicle and has no means to release. The mast attachment bracket relies on a friction clamp means to resist rotational forces and is likely to fail in all but light breezes. The overall sail design suffers in that it is fully symmetric about its mid-height point, from top to bottom. This is a result of the unusual requirement to rotate the sail's topside into the downward position as it tacks and jibes. The space required for the long boom to be fully extended outward in a running position, and then jibed from side to side will restrict the vehicle to roadways with a minimum of three meters of side clearance from obstacles.
U.S. Pat. No. 4,735,429 (Beck, 1988), is a rear-positioned sail rig with a wing like shape. This device unsuccessfully attempts to eliminate the operator's need to maintain continuous sail trim by an automatic self-positioning flexure means. As a result, the sail cannot be continuously trimmed, and there is no means to fully release the force of the wind. If the sail could be released while running it would swing forward striking, and pinning the rider against the vehicle. This system might permit limited upwind sailing success in light winds. However, there is no apparent means to control the sail or boom outward, and therefore it cannot reach, or run, or jibe properly.
U.S. Pat. Nos. 4,634,136 (Alexander, 1987) and 4,738,460 (Alexander, 1989) present design solutions which utilize sails mounted directly to the rider. Both are rear positioned rigs, mounted to the riders back, and suffer from many of the design flaws previously stated. They do not provide realistic sailing solutions.
Other Patents apply to sails mounted to other unique types of land vehicles. However, the nature of the design requirements and limitations of the performance criteria of a sailing bicycle, cycle and the like, make it unique from these other solutions.
U.S. Pat. No. 2,443,565 (Land, 1945) is a four wheel cycle, with a pedal means of propulsion. The unusual design uses a long, four sided truss-like frame. Steering is by means of a long tiller. The sail is a rear positioned, but forward facing. This solution has many of the previously stated problems associated with rear mounted sail rig. The configuration appears only possible of down wind sailing. Additionally, there is no adaptability to a standard bicycle or pedal cycle.
U.S. Pat. No. 3,986,722 (Patterson, 1976) is a unique non-standard two wheeled vehicle, with a forward positioned sail. This mast utilizes a permanently welded mast support bracket affixed to and made an integral part of this unique cycles' frame structure. There is no adaptive means suggested that permit its attachment to a standard bicycle. The mounting position and rearward raked slope of this bracket would prevent a standard bicycle handle bar from performing proper steering operations. As a result, this unique vehicle design requires a non-standard handlebar steering solution. The design also places a long footed sail and boom over the operator's head. This sail will develop a large rotational force about the vertical axis of the mast and over the operator's head, and which the operator has no physical means to overcome. The lack of standard sail sheet trimming eliminates the operators ability to effectively control the sail's leech tension, which is an important sail trimming function. This problem is compounded by the boom's length. To grasp the boom while running, the rider must operate the vehicle from a standing position. When the sail is fully released while running, it will swing uncontrollably forward and upward, fully beyond the reach of the operator. When beating, the operator must maintain pressure on the overhead boom in the physical equivalent of a continuous one arm pull-up. It appears that the vehicle is limited to use in only the lightest of breezes, and only by those operators possessing great physical strength. The non-standard cycle frame is lower than a conventional bicycle, and the necessary pedal means of propulsion has been omitted. The space required for the long boom to be fully extended outward in a running position, and then jibed from side to side, will restrict the vehicle to roadways with a minimum of four meters of side clearance from obstacles.
Thus, it can be concluded from the investigation of prior art, that no previous design exists, for a sail rig and its attachment to a standard bicycle, cycle, or the like, that can successfully utilize the wind's force to propel the vehicle, and that permit its full operation through all points of sail, and performance of all sailing maneuvers including tacking, jibing, and continuous sail trimming, with all of the safety and immediacy common to other sail vessels.
A need therefore exists for a bicycle or pedal cycle vehicle, with a sail rig and its attachments that can satisfy all of these stated criteria, and that can properly perform all of the functions characteristic of a true sailing vehicle for both recreational enjoyment and well as a practical mode of transportation.